* (The default weight is 1024 - so there's no practical
* limitation from this.)
*/
-#define MIN_SHARES 2
-#define MAX_SHARES (1UL << (18 + SCHED_LOAD_RESOLUTION))
+#define MIN_SHARES (1UL << 1)
+#define MAX_SHARES (1UL << 18)
static int root_task_group_load = ROOT_TASK_GROUP_LOAD;
#endif
/*
* Return the group to which this tasks belongs.
*
- * We use task_subsys_state_check() and extend the RCU verification
- * with lockdep_is_held(&p->pi_lock) because cpu_cgroup_attach()
- * holds that lock for each task it moves into the cgroup. Therefore
- * by holding that lock, we pin the task to the current cgroup.
+ * We use task_subsys_state_check() and extend the RCU verification with
+ * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each
+ * task it moves into the cgroup. Therefore by holding either of those locks,
+ * we pin the task to the current cgroup.
*/
static inline struct task_group *task_group(struct task_struct *p)
{
struct cgroup_subsys_state *css;
css = task_subsys_state_check(p, cpu_cgroup_subsys_id,
- lockdep_is_held(&p->pi_lock));
+ lockdep_is_held(&p->pi_lock) ||
+ lockdep_is_held(&task_rq(p)->lock));
tg = container_of(css, struct task_group, css);
return autogroup_task_group(p, tg);
!(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE));
#ifdef CONFIG_LOCKDEP
+ /*
+ * The caller should hold either p->pi_lock or rq->lock, when changing
+ * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks.
+ *
+ * sched_move_task() holds both and thus holding either pins the cgroup,
+ * see set_task_rq().
+ *
+ * Furthermore, all task_rq users should acquire both locks, see
+ * task_rq_lock().
+ */
WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
lockdep_is_held(&task_rq(p)->lock)));
#endif
}
rcu_read_unlock();
}
+
+ if (wake_flags & WF_MIGRATED)
+ schedstat_inc(p, se.statistics.nr_wakeups_migrate);
+
#endif /* CONFIG_SMP */
schedstat_inc(rq, ttwu_count);
if (wake_flags & WF_SYNC)
schedstat_inc(p, se.statistics.nr_wakeups_sync);
- if (cpu != task_cpu(p))
- schedstat_inc(p, se.statistics.nr_wakeups_migrate);
-
#endif /* CONFIG_SCHEDSTATS */
}
if (!next)
smp_send_reschedule(cpu);
}
-#endif
+
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+static int ttwu_activate_remote(struct task_struct *p, int wake_flags)
+{
+ struct rq *rq;
+ int ret = 0;
+
+ rq = __task_rq_lock(p);
+ if (p->on_cpu) {
+ ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+ ttwu_do_wakeup(rq, p, wake_flags);
+ ret = 1;
+ }
+ __task_rq_unlock(rq);
+
+ return ret;
+
+}
+#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
+#endif /* CONFIG_SMP */
static void ttwu_queue(struct task_struct *p, int cpu)
{
#if defined(CONFIG_SMP)
if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) {
+ sched_clock_cpu(cpu); /* sync clocks x-cpu */
ttwu_queue_remote(p, cpu);
return;
}
while (p->on_cpu) {
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
/*
- * If called from interrupt context we could have landed in the
- * middle of schedule(), in this case we should take care not
- * to spin on ->on_cpu if p is current, since that would
- * deadlock.
+ * In case the architecture enables interrupts in
+ * context_switch(), we cannot busy wait, since that
+ * would lead to deadlocks when an interrupt hits and
+ * tries to wake up @prev. So bail and do a complete
+ * remote wakeup.
*/
- if (p == current) {
- ttwu_queue(p, cpu);
+ if (ttwu_activate_remote(p, wake_flags))
goto stat;
- }
-#endif
+#else
cpu_relax();
+#endif
}
/*
* Pairs with the smp_wmb() in finish_lock_switch().
p->sched_class->task_waking(p);
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
- if (task_cpu(p) != cpu)
+ if (task_cpu(p) != cpu) {
+ wake_flags |= WF_MIGRATED;
set_task_cpu(p, cpu);
+ }
#endif /* CONFIG_SMP */
ttwu_queue(p, cpu);
idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
- cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
+ do_set_cpus_allowed(idle, cpumask_of(cpu));
/*
* We're having a chicken and egg problem, even though we are
* holding rq->lock, the cpu isn't yet set to this cpu so the
}
#ifdef CONFIG_SMP
+void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
+{
+ if (p->sched_class && p->sched_class->set_cpus_allowed)
+ p->sched_class->set_cpus_allowed(p, new_mask);
+ else {
+ cpumask_copy(&p->cpus_allowed, new_mask);
+ p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
+ }
+}
+
/*
* This is how migration works:
*
goto out;
}
- if (p->sched_class->set_cpus_allowed)
- p->sched_class->set_cpus_allowed(p, new_mask);
- else {
- cpumask_copy(&p->cpus_allowed, new_mask);
- p->rt.nr_cpus_allowed = cpumask_weight(new_mask);
- }
+ do_set_cpus_allowed(p, new_mask);
/* Can the task run on the task's current CPU? If so, we're done */
if (cpumask_test_cpu(task_cpu(p), new_mask))
if (!tg->se[0])
return -EINVAL;
- if (shares < MIN_SHARES)
- shares = MIN_SHARES;
- else if (shares > MAX_SHARES)
- shares = MAX_SHARES;
+ shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
mutex_lock(&shares_mutex);
if (tg->shares == shares)
git.openpandora.org / pandora-kernel.git / blobdiff